Slashdot videos: Now with more Slashdot!

View

Discuss

Share

We've improved Slashdot's video section; now you can view our video interviews, product close-ups and site visits with all the usual Slashdot options to comment, share, etc. No more walled garden! It's a work in progress -- we hope you'll check it out (Learn more about the recent updates).

sideshow2004 writes "EETimes is reporting this morning that IBM and Georiga Tech have demonstrated a 500 GHz Silicon-germanium (SiGe) chip, operating at 4.5 Kelvins. The 'frozen chip' was fabricated by IBM on 200mm wafers, and, at room temperature, the circuits operated at approximately 350 GHz."

I have to wonder about RF shielding. After all, even 802.11 gear runs at 2.4GHz, that's enough to cook ones private parts after extended use of a laptop. And with processors going in the same frequency range you can bet they're radiating RF. Luckily I made the decision not to have kids, but to those who might, you may want to reconsider resting that laptop in your lap.

After all, even 802.11 gear runs at 2.4GHz, that's enough to cook ones private parts after extended use of a laptop.

No, it isn't. 802.11 kit has an RF power output of around 100mW - absolute peanuts compared to your 800W microwave oven. The RF radiation from an 802.11 network isn't enough to cook anything.

What you might be referring to is the thermal output produced by a laptop, which is down to the CPU and hard drive rather than the 802.11 transmitter and that can cook your privates mostly through conduction, not radiation.

I think that's the point. Reading between the lines, this isn't about general-purpose CPU chips, this is about specialised signal processors. In other words, don't expect to be buying an Intel or AMD chip running at 30+GHz anytime soon.

This 500GHz chip is massively smaller than a general purpose CPU. With CPUs the size of the modern A64 or P4 (or Core for that matter), 500 GHz would be physically impossible without using some alternative to electricity to propagate signals or at least run async. Electricity literally doesn't flow across the chip fast enough. Now a 2 square millimeter DSP doesn't have near those issues.

Not really, because an EE would know that it's not just the RF output on a cellphone that works at 2.4 GHz, but also the signal processing unit. There is a digital system in the phone that natively controls the signal, rather than using older analog techniques. The general-purpose CPU for playing crappy java games and displaying inane text messages from your friends runs at something much lower than that, of course.

I initially thought that, but then realised that the article doesn't at any point describe what this chip actually does. So, I surmise that it isn't a general purpose processor (which would be a ridiculous leap forward: a processor that clocks in at around 200 times current-gen consumer systems?), but probably a digital signal processor of some kind. 500GHz might then be its sampling frequency, meaning that it could work with 250GHz signals. At this point, comparing its clock speed to the frequency of a

That's a pretty odd microwave then, since most of them operate at 2.45 GHz, which is chosen because of the way it causes liquid water molecules to vibrate. See this article [lsbu.ac.uk], particularly the graphs showing dielectric temperature as a function of frequency. It's pretty clear that a 10GHz microwave oven would be a lot less efficient at heating water than a conventional 2.45 GHz one, although I suppose you could choose a multiple of 2.45GHz and probably still have a functional product.

Overall, unless your goal was to build a miniature microwave (a 21st century E-Z Bake Oven?), I don't know why you'd want to use 10GHz instead of 2.4Ghz ones. The tolerances of parts in the magnetron and waveguide would have to be much tighter, I think, and this would almost certainly cause it to be more expensive.

Overall, unless your goal was to build a miniature microwave (a 21st century E-Z Bake Oven?), I don't know why you'd want to use 10GHz instead of 2.4Ghz ones. The tolerances of parts in the magnetron and waveguide would have to be much tighter, I think, and this would almost certainly cause it to be more expensive.

The heating would be more even potentially, but shallow. The other (obvious) thing I didn't think of in my earlier post was that as you increased the frequency, the waves would penetrate less far into the food, meaning that you'd have cold spots in the center. Maybe this would be useful for something (something that you'd want to cook the outside of but not the inside.. liquid-center cakes maybe?), but in general I think it would just be annoying.There are probably other molecules that you could heat by us

"By comparison, 500 GHz is more than 250 times faster than today's cell phones, which typically operate at approximately 2 GHz, according to the organizations."

And in other news, apples and oranges usually taste different.

The only question about computer speed that is important is, "Is it fast enough?" Of course, "fast enough" may change over time, and anytime you come up with a faster processor, some company like Microsoft will succeed in loading it down with bloatware. But I've got a customer who runs h

Oh come on! I got the (slightly lame) joke, but I just get pissed off when people keep repeating this fallacy of Moore's Law being clockspeed. Sorry if that makes me a bit anal, and yes, I do always think the Nazis like I was in this case tend to look a bit stupid, but it's like `rediculous' and `MAC' and `legos'... sometimes you just get irritated heheh.

By finding the last point on the temp/speed curve, they are able to much more accurately determine the entire curve. i.e. It's a lot easier to interpolate to more realistic cooling levels. And it makes for a cool headline too.

These are not microprocessors, and the achievement is not the amount of computing power you can get from them but the extremely high frequency of the signal they can generate. And that is not something you can increase by adding more chips!

I do believe that this is a DSP, or digital signal processor and hence the amount of information that can be had from a signal is dependent on the speed that the DSP runs at. It may seem overkill to sample a signal at 210x its frequency (assuming 2.4 GHz range), but that can allow for all manner of interesting signal encoding to help transmissions approach the Shannon limit and allow for more tunable transmission of data (meaning that you get the speed you need while investing as little energy as possible)

You are right, sort of. This could be useful for some very specialized processors that are very simple but need to do these simple operations very fast.

A CPU like the one we use now in PCs can't go much higher than 10GHz simply because, at light speed, an electron wouldn't have enough time to make it through the long circuit paths before the next clock cycle.

Actually they can't even do 1GHz at light speed. But that's why we have pipelining, and current generation have between 10-20 pipeline steps..

Not to mention that signals don't travel at c inside the chips. However, the signal path lengths can be decreased substantially by producing 3D integrated circuits. However, then heat dissipation becomes a real problem since there's more silicon for the heat to pass through before it gets to your heatsink. Of course this may not be a problem if your heatsink has a

at light speed, an electron wouldn't have enough time to make it through the long circuit paths before the next clock cycle.

It doesn't need to go through the long circuit path...

In fact, signals haven't gone through a whole path since (at the latest!) the 286. The processing is already divided into stages, and it only passes through one stage in each clock cycle. (Look up pipelining.)

It would be theoretically possible to design a chip that operated at a lot higher clock speed just by making the stages short

Everybody knows you can't trust ghz ratings. I mean, a 3.2 ghz athlon is clearly a bit faster than the 3.2 ghz pentium. Right? Oh, wait, you said.5 TERAHERTZ?!?! Oh, yeah, then I'll take one of those please. And that big ass freezer, thanks.

Hrm... a batch of transistors that'll relay at clock speeds of 350Ghz. Then they tossed on their P4 cooler and watched it superconduct. Why am I not surprised at 500Ghz? At 4.5K, it's clearly superconducting.
And the phone comparison... I like EE Times, but that writer needs to be shot. The editor deserves a slap on the wrists for letting it in (unless they're referring to some strange property of phones).
"For the first time, Georgia Tech and IBM have demonstrated that speeds of half a trillion cycles per second can be achieved in a commercial silicon-based technology, using large wafers and silicon-compatible low-cost manufacturing techniques,[and absurd cooling that allows us to leverage the properties of superconductivity]" (fixed).
IBM: Design it Today, Figure out what the hell we're going to do with it 7 years from Tomorrow.
(And yes, I'd get a microprocessor designed with these ubersistors).

Since these temperatures only occurs naturally in space, why not build a super, big cluster of these things, hook them up to a satallite and launch it into orbit.

Maybe because heat dissipation in space is poor? I know you can do magic with water evaporation under such low pressure to dissipate heat, but how much water would you need to send up there to provide cooling for reasonable time?

Radiation is a big issue for computers in space. Shielding equipment is heavy (=expensive to get up there), and the smaller (and faster) CPU's ICs become, the more susceptible to radiation they become.

There's a reason why NASA is trying their best to get their fingers on ancient CPUs.

IBM (Armonk, N.Y.) and Georgia Tech (Atlanta) claimed that they have demonstrated the first silicon-based chip capable of operating at frequencies above 500 GHz by cryogenically "freezing" the circuit to minus 451 degrees Fahrenheit (4.5 Kelvins).

Is anyone in the scientific world still seriously using Fahrenheit? What happened to si. Ok, for old farts like me it's nice to have the weather in Fahrenheit because I know that 60 is a nice spring day, 70 is hot and 80, phew, what a scorcher, but if I'm doing science I would no more use Fahrenheit than I would measure distance in poles.

"The achievement is a major step in the evolution of computer semiconductor technology that could eventually lead to faster networks and more powerful electronics at lower prices, said Bernard Meyerson, vice president and chief technologist in I.B.M.'s systems and technology group. He said developments like this one typically found their way into commercial products in 12 to 24 months."

I think I'll put off buying a new computer for a couple of years or so...

I just wanted to point that out, I think some posters are thinking about it incorrectly:
"The 500 GHz mark was the goal when Feng and UI colleagues received a $2.1 million, five-year grant for the project from the Defense Advanced Research Projects Agency in October. In contrast, the transistors inside the central chip of a powerful personal computer run at around 50 or 100 GHz, Feng said. The fastest that such a chip runs as a package is currently around 3 GHz."
http://www.news-gazette.com/news/local/2003/01/24/ fastest_transistor_made_at_ui/ [news-gazette.com]
In addition, University of Illinois broke 600 Ghz last year.
http://www.physorg.com/news3662.html [physorg.com]
"The speeds quoted in this article are maximum rated *switching* speeds of a single transistor. Synchronous logic designs of the type found in microprocessors involve synchronous cells (known as flip-flops) and asynchronous gates providing boolean functions on the signals passing between flip-flops. The maximum rated frequency of any design is limited by the slowest path between flip-flops and this is what the clock signal will be set at.
As the paths between the clocked flip-flops are typically anywhere between 2 and 10 logic cells deep and with each one comprising 10's of transistors (usually in complementary configuration to aid switching speed), the overall figure for an ASIC design such as a uProcessor would be at least 2-4 times slower than the maximum transistor switching speed (it's not quite cumulative, because as one transistor starts switching, the voltage at the at the `gate' of the next one has already started changing causing it to start conducting, and so on). I also have a suspicion that there would be other real-world constraints such as cross-talk (noise between transistors) and thermal problems. I'd hazard a guess that a production-quality chip would be somewhere in the region of a tenth the speeds quoted here!
However, these new materials and structures still make for an impressive speed gain over traditional Silicon CMOS designs." (The speeds quoted in this article are maximum rated *switching* speeds of a single transistor. Synchronous logic designs of the type found in microprocessors involve synchronous cells (known as flip-flops) and asynchronous gates providing boolean functions on the signals passing between flip-flops. The maximum rated frequency of any design is limited by the slowest path between flip-flops and this is what the clock signal will be set at.
As the paths between the clocked flip-flops are typically anywhere between 2 and 10 logic cells deep and with each one comprising 10's of transistors (usually in complementary configuration to aid switching speed), the overall figure for an ASIC design such as a uProcessor would be at least 2-4 times slower than the maximum transistor switching speed (it's not quite cumulative, because as one transistor starts switching, the voltage at the at the `gate' of the next one has already started changing causing it to start conducting, and so on). I also have a suspicion that there would be other real-world constraints such as cross-talk (noise between transistors) and thermal problems. I'd hazard a guess that a production-quality chip would be somewhere in the region of a tenth the speeds quoted here!
However, these new materials and structures still make for an impressive speed gain over traditional Silicon CMOS designs." (http://www.physorg.com/news3662.html)

That really is a great reference. With the ever increasing speed of processors these days, it would be useful to have a good reference unit, like horsepower. My desktop has 1 cellphonepower, but you can overclock an 805D to 2 cellphonepower!

1. Likely this will be a DSP, so if you try really hard, you'll get uCLinux to run on it, but it's not meant to do that, it will run dedicated assembly tasks best.2. No. Not enough cache mem, too slow RAM bus speeds.3. This is not a harddrive.

Yeah, incompetence is my guess here also. Most cell phones are running around a 500Mhz chip operating at a 2-2.4 Ghz transmit frequency.
Now saying that the chip is running 1000X faster than the chip in your cellphone would have been a good comparison, or some quote about the average PC chip being 2Ghz & this being 250X faster would have been good comparisons, but comparing the chip to the transmit frequency of the cell phone was stupid.

Didn't you ever think that if you had a digital signal entering your cell phone at 2.4 Ghz, you'd need a transistor in there that could switch at least that fast? You realize that there are other types of chips than microprocessors, right?

First, mobile phones do have extremely high frequency chips in them. They have to in order to recieve and process the high frequency signals they deal with. Those high frequency chips are a fairly large part of their power draw, too - yet their draw is *tiny* compared to even the simplest CPU of that clock. Remember that clock speed means very little without a consideration of the number of transistors on the chip, energy leakage rates, and lots more I know nothing about.You're making the erroneous equation